Method and system for determining component illumination settings

ABSTRACT

A method, a system and an archive server for determining an illumination setting for capturing an image of a component, belonging to a specific package type, in a pick- and-place machine are provided. The method comprises capturing a first image of a first component of the specific package type while the first component is illuminated by a first illumination component, and capturing a second image of the first component while the first component is illuminated by a second illumination component, the second illumination component being different from the first illumination component. An illumination setting may then be determined by creating a plurality of generated images based on the first and second image of the first component, and selecting the generated image that fulfils a predetermined quality measure.

FIELD OF THE INVENTION

The present invention generally relates to the field of pick-and-placemachines. More specifically, the present invention relates to a method,a system and an archive server for verifying components in a pick andplace machine.

BACKGROUND OF THE INVENTION

When mounting components on a printed circuit board using a componentmounting machine there is a need for close precision. In order toachieve this an image processing device is often used for obtaining andanalysing an image of the component after it has been picked up by meansof a mounting head. The aim of the analysis is to determine the type andposition of the component on the mounting head before it is mounted on aworkpiece. When the position of the component to be mounted is known,the component mounting machine can compensate for the translation androtation of the component before it is mounted on the printed circuitboard. Further, in the analysis the image of the component to be mountedcan be examined for faults, such as wrong component type, missing leads,erroneous leads or incorrectly positioned leads.

To ensure that the component is correctly picked up and that thecomponent itself is not of the wrong type or defective, the componentmay be lit from below or at an angle, photographed and then analyzed.Image analysis may the employed to verify the component. This requiredthe component mounting machine to be calibrated to find a good lightsettings that enables a correct image analysis. The light settings maye.g. be determined by capturing a number of images of the component withdifferent light settings, and using the best light setting forevaluating the component. This process may be error prone and timeconsuming, and there is no easy way of updating the calibration ifneeded.

Hence, there is a need for an improved calibration of light settings andan improved way of verifying for components in pick-and-place machines.

SUMMARY

An object of the present disclosure is therefore to mitigate some of thedrawbacks described above. To achieve this, a method, a system and anarchive server are provided. Further embodiments are defined in thedependent claims.

Hence, according to a first aspect, a method for determining anillumination setting for capturing an image of a component, belonging toa specific package type, in a pick-and-place machine is provided. Themethod comprises capturing a first image of a first component of thespecific package type while the first component is illuminated by afirst illumination component, and capturing a second image of the firstcomponent while the first component is illuminated by a secondillumination component, the second illumination component beingdifferent from the first illumination component. The method furthercomprises generating, by the use of software manipulation of the firstimage and the second image, a plurality of generated images of the firstcomponent, wherein each one of the plurality of generated imagescomprises a specific combination of an illumination intensity level ofthe first illumination component and an illumination intensity level ofthe second illumination component, selecting at least one of theplurality of generated images that fulfils a quality measure, anddetermining, based on the selected generated image, an illuminationsetting associated with the package type, wherein the determinedillumination setting comprises a first intensity level for the firstillumination component and a second intensity level for the secondillumination component.

According to a second aspect, a system for verifying components,belonging to a specific package type, in a pick-and-place machine, isprovided. The system comprises a first illumination source forilluminating a first component of the specific package type by a firstillumination component and a second illumination source for illuminatingthe first component by a second illumination component, the secondillumination component being different from the first illuminationcomponent. The system further comprises a camera for capturing a firstimage of the component while illuminated by the first illuminationcomponent and a second image of the component while illuminated by thesecond illumination component. The system further comprises a processingmeans configured to generate, by the use of software manipulation of thefirst image and the second image, a plurality of generated images of thefirst component, wherein each one of the plurality of generated imagescomprises a specific combination of an illumination intensity level ofthe first illumination component and an illumination intensity level ofthe second illumination component and select at least one of theplurality of generated images that fulfils a predetermined qualitymeasure. The processor is further configured to determine, based on theselected generated image, an illumination setting associated with thepackage type, wherein the determined illumination setting comprises afirst intensity level for the first illumination component and a secondintensity level for the second illumination component.

With the present inventive concept, an illumination setting for acomponent may be determined based on a relatively small number ofcaptured images. The images captured with different illumination modescorrespond to different illumination settings for the illuminationsources and may be used by software to generate and determine an imagethat fulfils certain quality measures. The generated image correspondsto different intensity settings for the different illuminationcomponents, which allow for an optimal illumination setting to bedetermined. In this way, the calibration of the illumination used by thepick and place machine may be automated, and the time and effort forcalibrating the machine may thereby be decreased.

It has been realized that with software and a small number of referenceimages, i.e. the images captured with different illumination components,a high number of possible images (i.e., combinations of illuminationsettings) may be generated. Software may generate a plurality of imagesbased on the first and second images and determine which one of thecomputer generated images that fulfils the quality demands. This image,which this may be a combination of the reference images, correspond to aparticular illumination setting, according to which the differentillumination sources may be operated. Hence, different availableillumination settings may be evaluated in software without having tocapture a vast number of images of the component illuminated with fixedillumination settings. Instead, images may be software generated toevaluate different simulated illumination settings for the illuminationsources.

In prior solutions, the calibration of the illumination setting for acomponent of a package type in a pick and place machine is done manuallyby adjusting the light settings, capturing a vast number of images withfixed illumination settings, and finally deciding on a setting that isgood enough. As this is a manual process, it may be error prone andthereby causing a high percentage of false negatives, i.e. componentsare discarded as incorrectly aligned or defective when they should havebeen mounted. Further, if one light setting seems to be incorrect whenlater used in the pick and place machine, there is no simple way ofadjusting the light setting again, but the process has to be restartedfrom the beginning. Alternatively, the vast number of images may bestored in a database, but that may quickly be unmanageable.

The present inventive concept is associated with several advantages.First, as, described above, the calibration of the illumination settingsfor a pick and place machine may be automated, and the time and effortfor calibrating the machine may thereby be decreased.

Second, as the process of calibrating the pick and place machine isautomated, the number of errors in calibration may be decreased and thedetail level may be increased—especially in comparison with manualcalibration of the illumination settings. The number of images that canbe evaluated is increased when the process is automated, enabling forfinding a better image for evaluating the component, and therebydetermining a better illumination setting.

Third, as only a small number of images is needed, for example one or afew for each illumination component, the images may be stored for lateruse or recalibration of the pick and place machine. With the imagesstored, the calibration as described above may be performed based onthose images at a later point in time, or they may be used as trainingor verification data for a machine learning algorithm, thereby improvingthe algorithm for generating illumination settings.

A “pick and place machine” may be any pick and place or mounting machinesuitable for mounting components on a workpiece. It should be noted thatthe present inventive concept may be used regardless of the type of pickand place machine, the mounting head type or the type of feeding in themachine.

In the present specification, the term “component” may refer to anelectric component to be mounted on a workpiece. The component may e.g.be delivered on a tray or component tape, and transported to the pickinghead by a component feeding mechanism.

A “package” should be understood as the chip carrier or encapsulation ofthe chip, which together with the chip may form the component. Thepackage may comprise contacting means, such as e.g. pins, leads orcontacts through which the component may be operably connected to theworkpiece. A “package type” refer to the type of package in terms ofe.g. physical dimensions, functional characteristics of the component,lead pitch, case materials, contact types, etcetera. Information of suchcharacteristics may also be referred to as package data. The packagetypes for components may further be divided into families with common orsimilar characteristics. It will be appreciated that, according toembodiments of the present invention, the package data may becomplemented with the determined illumination settings.

By “workpiece” it is meant, for example, a printed circuit board orsubstrate, or other piece of material that components may be mounted on.

By “quality measure” it may be meant predetermined features of an image,such as contrast, color, brightness, or similar, or it may bepre-generated quality measures as determined by a machine learningalgorithm.

It will be appreciated that an “illumination component” or “illuminationmode” may be refer to a specific illumination condition of the electriccomponent. The illumination condition may be generated by one or severalillumination sources or illumination arrangements, and may e.g. becharacterized by the combination of color, angle of incidence, intensityor other parameters affecting the imaging of the component.

The determined illumination setting may use different illuminationsources with different intensities to form a specific illuminationcondition of the component. As an illustrative example only, theillumination setting may comprise a first illumination setting for thefirst illumination source, for example 50% of maximum intensity, and asecond illumination setting for the second illumination source, forexample an intensity of 75% of maximum.

The first image of the first component when illuminated by the firstillumination component and the second image of the first component whenilluminated by the second illumination component may in the presentapplication be referred to as “reference images”.

It will be appreciated that the system according to the second aspect ofthe present disclosure may be referred to as “verification system”.

According to a third aspect, an archive server is provided. The archiveserver has at its disposal a first communication interface adapted toreceive, from a system as described with reference to the second aspect,an illumination setting associated with a first component of a specificpackage type, a storing unit adapted to store the illumination setting,and a second communication interface adapted to provide the illuminationsetting upon request by a user. The archive server may be any type ofserver, local or remote to a pick and place machine, capable ofreceiving and serving data. The archive server may be capable ofreceiving data from multiple pick and place machines.

In this way, the archive server may receive an illumination settingassociated with a component of a package type or component type. Thearchive server may receive data from one or several pick and placemachines. The received illumination settings may be stored and reused byother users and pick and place machines. By reusing illuminationsettings, the time and effort for calibrating pick and place machinesmay be decreased.

According to an embodiment of the first aspect, the method according tothe first aspect may further comprise the subsequent steps of capturingan image of a second component of the specific package type while thesecond component is illuminated according to the determined illuminationsettings, and determining, based on an analysis of the captured image,whether the second component shall be discarded or placed on aworkpiece. These steps may also be referred to as “verification steps”,as it is determined if a component should be discarded or placed on aworkpiece, i.e. verifying the correctness of the component.

The analysis of the captured image may be a static algorithm based onpredetermined parameter, such as orientation, number of leads, thepresence of a marking, etc, or it may be based on a machine learningalgorithm trained on similar data sets (as for example retrieved from anarchive server storing information from a plurality of users).

By using the determined illumination setting when capturing the image ofthe component as held by the mounting head, it can be determined, byanalysis of the captured image, if the component should be discarded orplaced on a workpiece. This allows for decreasing the number of faultyor incorrectly picked components, thereby avoiding mounting erroneouscomponents and increasing the quality of the product.

According to an embodiment, the method further comprises capturing, incase it is determined that the second component shall be discarded, averification image of the second component while the second component isilluminated according to a verification illumination setting, anddetermining, based on an analysis of the captured verification image,whether the second component shall be discarded or placed on theworkpiece.

In this way, a determination that a component should be discarded may beevaluated a second time with a second, i.e. a verification, illuminationsetting that may be specific for determining certain errors, for examplethat the component is incorrectly picked up, or an illumination settingspecific for determining that all leads are correct. With thisverification image, as the illumination setting may be different fromthe first image, a better analysis may be performed for the specificproblem as determined by the first image. In other words, it can bedetermined if the second component should have been determined to bediscarded. If it is determined that the component should not have beendiscarded in the previous step, the component may be mounted. In thisway, the number of false negatives may be decreased.

According to an embodiment, the captured image may be analysed withregard to at least one of the following parameters: shape or outline ofthe component, or position or orientation as held by a mounting head ofthe pick-and-place machine.

By analyzing the shape or outline of the component it may be determinedwhether the component is of the expected type, if the component itselfis defective or not, for example if the component have all the expectedleads, if it has the expected shape, or similar visual features forverifying it. By determining the position or orientation of thecomponent as held by the mounting head it may be determined if thecomponent was correctly picked up. Even if the component itself is notdefective, it may not be suitable for mounting if it was not correctlypicked, for example if it has a too large rotation in comparison to theexpected position.

With this analysis, faulty or incorrectly picked up components may bediscarded, thereby avoiding errors in the product assembled by the pickand place machine.

According to an embodiment, the first component may be held by amounting head of the pick-and-place machine during the capturing of thefirst and second images.

The images of the first component may in this way be captured in thesame way as they will be used when verifying subsequent components, i.e.as held by the mounting head.

As the images are captured in the same component both when calibratingthe machine and when verifying the components in a later step, theimages may be more relevant and the generated images, and thereby thedetermined illumination setting, may be of higher quality, i.e. bebetter for evaluating the components. Higher quality images may lead tofewer errors in the determination of whether a component should bemounted or not.

According to an embodiment, the predetermined quality measure maycorrespond to a highest image contrast. Thus, the generated images maybe evaluated for contrast, and the selected image may correspond to theone having the highest contrast.

With a high contrast in the selected image, the illumination setting maybe selected such that the captured images are images with highcontrasts. This may improve the evaluation of if the component isdefective, for example is missing or having a defect lead, and todetermine the orientation and position of the component in the mountinghead.

According to an embodiment, the method further comprises capturing abackground illumination image of the first component, and subtractingthe background illumination image from the first image and the secondimage prior to the generating of the plurality of generated images.

A background image may be an image captured without activelyilluminating the component by any of the illumination sources, such thatthe component is only illuminated by background light. By subtractingthe background illumination image form the captured images, backgroundnoise or background light, i.e data irrelevant for the intensity of theimages relative to each other, may be removed. Removing the backgroundimage may also improve the quality of the generated images as thebackground is not accounted for several times (one for each image usedwhen generating the generated images). The background image may besubtracted from the first and second images before the generated imagesare provided by means of the software. This allows for higher qualitygenerated images and facilitates the determining of optimal illuminationsettings, which in turn may improve the verification of the components,i.e. if a component should be mounted or discarded.

According to an embodiment, the background illumination image is addedto the selected one of the plurality of generated images that fulfilsthe quality measure. The resulting image may then be stored as areference image to be used when determining whether a subsequentcomponent of the specific package type shall be discarded or placed on aworkpiece.

As the background illumination, or the background light, will be presentwhen capturing images of the second component, adding the backgroundillumination image to the generated images before evaluating them basedon the quality measure, the determined illumination setting based onthat images may better correspond to the images captured when verifyingcomponents.

According to an embodiment, the intensity level of the firstillumination component, during the capturing of the first image, may beselected such that at least some pixels of the first image are saturatedor almost saturated, and/or the intensity level of the secondillumination component, during the capturing of the second image, mayselected such that at least some pixels of the second image aresaturated or almost saturated. This may be considered to be the maximumintensity for that illumination component, and thereby the maximumintensity that can be determined and used when verifying components.

Having the intensity levels of the illumination components be as high aspossible, for example, as high as possible to capture by the images in arelevant way without loosing granularity, the possible combinations ofimages is increased. For example, using 80% of the illumination maximumintensity for an illumination source when capturing an image, gives apossible determined illumination setting between 0-80%, whereas if a100% of the illumination setting for the illumination source would havebeen used, the possible determined illumination setting may be between0-100%.

According to an embodiment, the first illumination component representsillumination of the component from a first angle and the secondillumination component represents illumination of the component from asecond angle, the second angle being different from the first angle. Byusing different angles for the illumination components, different partsof the component may be lit or highlighted.

This allows for further improving the generated images, as more parts ofthe component may be visible with the different illumination components.When the quality of the selected generated image may increase, theillumination setting may be better determined, and the evaluation of thesecond component may be improved.

According to an embodiment, the first illumination component representsillumination with light of a first colour and the second illuminationcomponent represents illumination with light of a second colour, thesecond colour being different from the first colour.

By using different colors for the illumination components, differentparts of the component may be highlighted, have higher contrast ordifferent colors may be more visible. This allows for further improvingthe generated images, as more parts of the component will be visiblewith the different illumination components. When the quality of theselected generated image may increase, the illumination setting may bebetter determined, and the evaluation of the second component may beimproved.

According to an embodiment, the method further comprises uploading thedetermined illumination setting to an archive server. An archive servermay be any type of server capable of receiving and storing theillumination settings to be uploaded.

By uploading the illumination setting to an archive server, theillumination setting may be reused and thereby decreasing the time forcalibrating another pick and place machine. More details regarding thearchive server will be described below with reference to a third aspectof the invention.

If it has been determined that a component should be discarded, themethod may further comprise uploading the reference images, i.e. thefirst and second images captured of the first component, to the archiveserver and uploading the captured image or images based on which thedetermination to discard the component has been made. In this way, theimages may later be reused to improve the algorithm for determiningillumination settings or the algorithm for determining whether acomponent should be mounted or not. In a similar way, data may also besent to an archive server when a component is determined to be mounted.

According to an embodiment, the first and second illumination componentsare selected from the list comprising: dark field illumination, frontlight illumination, and ambient illumination. By dark field illuminationit may be meant that the component is illuminated by light from thesides of the component, which causes the component to appear lightagainst a dark background. The front light illumination may beillumination from the same angle as the camera, i.e. from the frontside. Ambient illumination may mean illumination from different sides ofthe component.

According to an embodiment of the second aspect, the camera is furtheradapted to capture an image of a second component of the specificpackage type while the second component is illuminated according to thedetermined illumination setting, and wherein the the processing means isfurther configured to determine, based on an analysis of the capturedimage of the second component, whether the second component shall bediscarded or placed on a workpiece.

The analysis of the captured image by the processing means may be astatic algorithm based on predetermined parameter, such as orientation,number of leads, the presence of a marking, etc, or it may be based on amachine learning algorithm trained on similar data sets.

By using the determined illumination setting when capturing the image ofthe component as held by the mounting head, it can be determined, byanalysis of the captured image, if the component should be discarded orplaced on a workpiece. This allows for decreasing the number of faultyor incorrectly picked up components, thereby avoiding mounting erroneouscomponents and increasing the quality of the product.

According to an embodiment of the third aspect, the storing unit of thearchive server is adapted to store package data relating to the firstcomponent, and to complement the package data with one or severalillumination settings associated with the first component. In this way,data regarding different components of the same package type may beinterrelated.

According to an embodiment, the archive server further has at itsdisposal a third communication interface adapted to receive, from thesystem according to the second aspect, the images of a componentcaptured by the camera when illuminated by the first and secondillumination components. Via the third communication interface, thearchive server may receive reference images, verification images orother types of images as captured by a pick and place machine.

For example, the reference images as captured when calibrating the pickand place machine for a new component may be received by the archiveserver via the third communication interface.

For another example, when a component is rejected, it is unclear ifother light settings could result in better images to make theverification system take better decisions. If images of all componentsthat are rejected are stored together with the reference images in thearchive server, it allows for further processing of the data todetermine better illumination settings, which may lead to fewer falsenegatives or false positives.

The received or collected data may be used for optimizing or improvingalgorithms for determining whether components should be discarded ormounted, and for algorithms for determining preferred illuminationsettings for a specific component type or a specific component of apackage type. The data may also be used as training or verification datafor machine learning algorithms for determining preferred illuminationsettings or whether components should be discarded or mounted.

The inventive concept disclosed may be embodied as computer readableinstructions for controlling a programmable computer in such manner thatit causes a pick and place machine, a system or an archive server asdescribed above, to perform the methods outlined above. Suchinstructions may be distributed in the form of a computer programproduct comprising a non-volatile computer-readable medium storing theinstructions.

It will be appreciated that any of the features in the embodimentsdescribed above for the method according to the first aspect may becombined with the system according to the second aspect of the inventiveconcept disclosed.

Further objectives of, features of, and advantages with the presentinventive concept will become apparent when studying the followingdetailed disclosure, the drawings and the appended claims. Those skilledin the art will realise that different features of the present inventiveconcept can be combined to create embodiments other than those describedin the following.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, as well as additional objects, features and advantages of thepresent inventive concept, will be better understood through thefollowing illustrative and non-limiting detailed description ofpreferred embodiments of the present inventive concept, with referenceto the appended drawings. In the drawings like reference numerals willbe used for like elements unless stated otherwise.

FIG. 1 shows a pick and place machine according to an embodiment.

FIG. 2 illustrates a verification system according to an embodiment.

FIG. 3 illustrates a method for determining an illumination settingaccording to an embodiment.

FIG. 4 illustrates a method for verifying a component for mounting.

FIG. 5 illustrates a method for handling component data.

FIG. 6 is an overview of an archive server.

All the figures are schematic, not necessarily to scale, and generallyonly show parts which are necessary in order to elucidate theembodiments, wherein other parts may be omitted.

DETAILED DESCRIPTION OF EMBODIMENTS

Detailed embodiments of the present inventive concept will now bedescribed with reference to the drawings. The present inventive conceptmay, however, be embodied in many different forms and should not beconstrued as limited to the embodiments set forth herein; rather, theseembodiments are provided by way of example so that this disclosure willconvey the scope of the inventive concept to those skilled in the art.

Embodiments of the present inventive concept generally relate to amethod and a system for calibrating illumination settings for componentsand verifying components using the determined illumination setting in apick and place machine. Such pick and place machines generally comprisea mounting head 110, an illumination source 130 or multiple illuminationsources, a camera 140, and processing means 120. A component 160 to bemounted may be picked up by a mounting head 110, and illuminated by theillumination sources 130 while one or more images are being captured bythe camera 140.

The mounting head 110 may comprise a vacuum nozzle for picking up thecomponent 160. The component 160 may be picked, for example, from acomponent feeder 170 or from a component tape holding components. Themounting head 110 may subsequently place the picked component on asubstrate 180, such as a printed wire board or a workpiece (not shown).The mounting head 110 is further arranged to move the component 160 inthe field of view of the camera 140 prior to the component is mounted onthe workpiece.

The camera 140 may be a line scan camera which the mounting head holdingthe component passes one or a plurality of times, or an area camera. Aline scan camera may contain a single row of pixels used to capture dataquickly. As an object moves past the camera, a complete image can bereconstructed in software line by line. An area camera may contain amatrix of pixels that capture an image of a given object. For an areacamera to capture an image of an object the object may need to bestationary. The images may be captured when the mounting head 110holding the component 160 passes the camera, or the mounting head maystop by the camera.

The illumination sources 130 may be arranged to provide differentillumination conditions formed by one or several illuminationcomponents. The specific illumination conditions provided may e.g.depend on the positioning (and number) of the illumination sources 130,the intensity of the light they generate, and color. The illuminationsources 130 will be further discussed in the following.

The processing means 120 may be configured to perform at least some ofthe steps in the methods described below.

FIG. 2 shows an overview of a verification system in a pick and placemachine 100 that may be similarly configured as the pick and placemachine discussed in connection with FIG. 1. The pick and place machine100 may hold a component 160 with mounting head 100. The component maybe picked up from a magazine 170 for mounting on a workpiece 180, or forcalibration of illumination settings for the pick and place machine 100.The pick and place machine may comprise illumination sources 130, 131,132, 133, 134, 135 and a camera 140.

The illumination sources 130, 131, 132, 133, 134, 135 may comprise LEDlights or LED panels, or other means suitable for illuminating acomponent. The illumination sources may be operable to provide differentillumination components or illumination conditions. In one example,illumination sources 131, 132 form a darkfield illumination component,illumination sources 133, 134 form an ambient illumination component,and illumination source 135 (in this example including a semitransparentmirror 136 guiding the light to the intended angle) form a frontlightillumination source. By dark field illumination it may be meant that thecomponent is illuminated by light coming from the sides of the component(as seen from the camera), which may causes the component to appearlight against a dark background. The front light illumination may beillumination from the same angle as the camera, i.e. from the frontside. Ambient illumination may mean illumination from different sides ofthe component.

An image of the component 160 may be captured by a camera 140. Thecomponent may be illuminated by none, one, a plurality of all of theillumination sources 130, 131, 132, 133, 134, 135 with differentintensities. An illumination source may be used for generating one ormore illumination component. An illumination component may be formed byone or more illumination sources.

The camera may send the captured image data to the processing means 120.

A method 200 for determining an illumination setting for a component ofa package type according to an embodiment will be described withreference to FIG. 3. The method may be performed when calibrating orrecalibrating the machine for a component of a package type. Forexample, when a new package type is to be mounted by the machine, orwhen it has been realized that the previous calibration was notsufficient.

The method may at least partly be performed by a processing means 120 ofa pick and place machine 100. The processing means 120 may be integratedin the pick and place machine 100, or be physically separated from thepick and place machine. Further, the processing means may bestructurally integrated as one unit or structurally distinct, i.e.,physically separated and/or located in different physical orgeographical positions, even if connected or being connectable to eachother via e.g. a communication network.

The method comprises a step 210 of capturing a first image of acomponent 160, held by a mounting head 110 and illuminated by anillumination source 130 with a first illumination component, by a camera140. The first illumination component may for example be ambient light,as produced by illumination sources 133 and 134. The method may furthercomprise a step 220 to capture a second image of a component 160, heldby the mounting head 110 and illuminated by an illumination source 130with a second illumination component, by camera 140. The secondillumination component may for example be frontlight, as produced byillumination source 135 and a mirror 136 to direct the light.

The first image of the first component when illuminated by a firstillumination component and the second image of the first component whenilluminated by a second illumination component, or other images capturedof the component when illuminated with other illumination components,may in the present application be referred to as “reference images”. Thereference images may correspond to maximum illumination of a specificillumination source or arrangement.

Optionally, the method comprises further steps 230 of capturing furtherimages of the component illuminated by different illuminationcomponents. For example, a background illumination image may becaptured. When capturing the background illumination image, none of thelight sources 130, 131, 132, 133, 134, 135 are used, i.e. the componentis only illuminated by background light. Also other illuminationcomponents, for example other colors or angels, may be used forcapturing other reference images.

Steps 210-230 may be performed in any order.

The intensity of the illumination, i.e. the brightness of theillumination sources, may be set such that at least some pixels in eachof the captured images are saturated or almost saturated. This may alsobe referred to as the maximum intensity of the illumination, as anyhigher intensity may cause information for different pixels to be lostand decrease the granularity of the image.

The method further comprises a step 240 of generating a plurality ofgenerated images based on the captured images of steps 210-230. Thegenerated images may be any combination of the images with differentintensities. As an illustrative example only, each of the images may beincluded with 0-100% in a generated image, for example with 1 pointintervals, where 100 is the maximum intensity, i. e. the image ascaptured, and 0 is no inclusion. If steps 210-230 captured 3 differentimages with different illumination settings, each of the three imagesmay be included in a generated image with one of 0-100%. Thus,100*100*100=1 000 000 images could be generated with different simulatedcombinations of the captured images, or reference images. The positionof the component in the different captured images may be exactly thesame, or approximately the same, or the images may be adjusted so thatthe position of the component in the images is exactly, orapproximately, the same. To create a generated image where the componentis clearly visible, the component should preferably be in the same placein all of the images that are used for blending or combining into agenerated image.

Generating 240 the plurality of generated images may also comprisesubtracting the background image, if any, from the reference images. Thereference images may then be combined, and the background image may beadded. In this way, the background image light is not accounted for morethan once.

When, or at the same time as, the generated images have been generatedfrom the reference images, the generated images are scanned for qualityparameters or quality measures and one is selected in step 250. Qualityparameter or measures may, for example, be predetermined features of animage, such as contrast, color, brightness, or similar, or it may bepre-generated quality measures as determined by a machine learningalgorithm.

Each of the images may be scanned 521 for the quality measures todetermine 252 the best one, i.e. the best one based on the qualityparameters, or the images may be scanned until an image that fulfils thequality measures have been found. If an image fulfils the qualitymeasures it may be used 254, otherwise the image may be discarded 253.If no image fulfils the quality parameters, the best image with respectto those parameters may be used. The images may be generated based onprevious data of which intervals may be suitable in order to increasethe speed of the generation.

Once a generated image has been selected, illumination settings for thepackage type or component type may be determined 260 based on thegenerated image. The illumination setting for a package type orcomponent type comprises settings for the illumination sources or modes.For example, if the generated image uses 75% of the full intensity ofimage A, captured with illumination arrangement A, and 50% of the fullintensity of image B, captured with illumination arrangement B, anillumination setting of 75% of maximum intensity for illuminationarrangement A and 50% of maximum intensity for illumination arrangementB may be determined. Hence, the level in which the images are used inthe selected generated image may correspond to intensity levels of thedifferent intensity levels used when capturing the reference images usedto generate the generated image.

Optionally, the determined illumination setting or captured images maybe sent 270 to an archive server 500 and/or the reference images may besent to the archive server 500. The archive server 500 may be any typeof server capable of receiving the determined illumination setting. Thearchive server 500 may store the illumination setting or images and thedata may later be used for improving the algorithms for the methodsdescribed. More details about the archive server 500 will be describedin detail with reference to FIG. 6.

The determined 260 illumination setting for a component type or packagetype may be used in a method for verifying a component of a package typeor component type before mounting, as described with reference to FIG.4.

With reference to FIG. 4, a method 300 for verifying a component formounting is described, according to an embodiment that may be similar tothe embodiments discussed in connection with the previous figures. By“verifying a component” may be understood to determine that thecomponent is not defective, that the component is of the expectedpackage type, and that the component is correctly picked up by themounting head. The method may be performed by a pick and place machinebefore mounting a component. By verifying the component before mountingit on a workpiece, faulty workpieces may be avoided or decreased.

The method may comprise a step in which a component is picked up 310 bya mounting head 110. An image of the component, using a determinedillumination setting, may be captured 320. The captured image of thecomponent may be analyzed 330, for example by the processing means 120of the pick and place machine 100. The image may be analyzed bycomparing it to a known image of the component, for example as providedby the archive server 500 or from a database. Alternatively, oradditionally, the image may be analyzed by an algorithm identifying, forexample, the shape, identity, type, position or orientation of thecomponent in the captured image. Based on the analysis of the image itmay be determined 340 if the component should be mounted or discarded.If the component is determined to be defective, not of the expected typeor if it is incorrectly picked up, it may be discarded. Otherwise, thecomponent may be mounted. If it is determined that the component shouldbe mounted, it may be mounted 350 on a workpiece.

If it is determined that the component should not be mounted, a secondimage, a verification image, may be captured 370, using a secondillumination setting. The second illumination setting may be selectedbased on the fault found by analyzing 330 the captured image. The secondillumination setting may have been determined using the method 200 fordetermining illumination settings but with different quality measuresthan used when determining the first illumination setting.

For example, if it is determined in step 330 that the component wasincorrectly picked up, an illumination setting suitable for determiningif the component is indeed correctly picked up may be used. If it isdetermined by the analyzing the verification image that the component isnot incorrectly picked up, it may be mounted, otherwise it may bediscarded. When it has been determined that the component may bediscarded, a method 400 for handling the data for the component may beinitiated, as described with reference to FIG. 5.

With reference to FIG. 5, a method 400 for handling data regarding acomponent is described, according to an embodiment. The method 400 maybe performed by the processing unit 120 of a pick and place machine 100similar to the pick and place machines discussed with reference to theprevious figures, and by a processing means 510 in an archive server500. With data it may be meant any type of data regarding a component, acomponent type, a package type or any other data that may be relevantfor a pick and place machine.

When a component has been determined to be discarded, new referenceimages may be captured for the component. The new reference images maybe sent to the archive server 500. The captured images of steps 320 and370 may also be sent to the archive server 500, together with anyprevious reference images. The images may be tagged 420, for example bya user with knowledge of the components, and the tags may indicatewhether the determination not to mount (or to mount if that was thedecision) was correct or not.

The algorithm for determining illumination settings, if it is a machinelearning algorithm, may be trained 430 based on the tagged data, forexample with a supervised learning algorithm. Alternatively, if it is astatic algorithm, the algorithm may be changed, and verified with thetagged data. The updated algorithm may then be used 440 in the method200 for determining an illumination setting, as described with referenceto FIG. 3.

The algorithm for determining whether a component should be mounted on aworkpiece or not may, similarly as described above, if it is a machinelearning algorithm, be trained 450 based on the tagged data, for examplewith a supervised learning algorithm. Alternatively, if it is a staticalgorithm, the algorithm may be changed and verified with the taggeddata. The updated algorithm may be used 460 in the method 300 fordetermining if a component should be mounted or not, as described withreference to FIG. 4.

The method 400 as described above is described for when a component hasbeen determined to be discarded, but the method 500 may also beperformed irrespectively if the component has been determined to bediscarded or not, that is, the same data and images (if captured) may besent to the archive server even if the component was mounted. This datamay be used, by, for example, a developer of pick and place machines, totrain algorithms on positive datasets.

An archive server 500, according to an embodiment, will be describedwith reference to FIG. 6. The archive server 500 comprises a processingmeans 510, a storing unit 530, and, in this example, three communicationinterfaces 520, 521, 522, 523. However, other numbers of interfaces withdifferent functionality may be used. For example, the three interfacesmay be one interface with a combined functionality of the three examplesdescribed here. The interfaces could be any type of communicationinterfaces suitable for sending and/or receiving data. For example, aninterface may be an API, an endpoint, or a file system.

The storing unit 530 may be any type of storing unit configured to storedata. For example purposes only, the storing unit may be a database or afile system. The storing unit may be in the same server as the archiveserver, or may be on one or more servers. The storing unit 530 may beadapted to store package data relating to the first component and tocomplement the package data with one or more illumination settingsassociated with the first component. Also further data may be stored inthe storing unit 530, which may be related to the first component or thepackage type of the first component.

The archive server 500 may receive, through the first communicationinterface 521, an illumination setting associated with a first componentof a specific package type, for example from a pick and place machine100. The received illumination setting may have been determined by thepick and place machine 100 using the method 200. The receivedillumination setting may be stored, for example by the processing unit510, in the storing unit 530. The archive server 500 may provide theillumination setting through a second communication interface 522adapted to provide the illumination setting upon request from a user.The user may be a person using a software or an application requestingthe data.

The archive server may, through a third communication interface 523,receive images of a component captured by a camera when illuminated byan illumination component. The images may be reference images or imagesof a component when illuminated by illumination sources 130 of a pickand place machine 100, as per determined illumination settings with themethod 200. The received data may be stored in the storing unit 530. Thereceived data may be used for improving algorithms for determiningillumination settings or verifying components, for example, by beingused as training or verification data for a machine learning algorithm,or being used as verification data for a static algorithm.

As described with reference to FIG. 5, the archive server may store andprovide data to the method 400 to improve algorithms for determiningillumination settings and/or whether a component should be discarded ornot.

The person skilled in the art realizes that the present invention by nomeans is limited to the embodiments described above. On the contrary,many modifications and variations are possible within the scope of theappended claims.

Additionally, variations to the disclosed embodiments can be understoodand effected by the skilled person in practicing the claimed invention,from a study of the drawings, the disclosure, and the appended claims.In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality. The mere fact that certain measures are recited in mutuallydifferent dependent claims does not indicate that a combination of thesemeasures cannot be used to advantage.

Itemized Embodiments

1. A method for determining an illumination setting for capturing animage of a component, belonging to a specific package type, in apick-and-place machine, the method comprising:

capturing a first image of a first electronic component of said specificpackage type while the first electronic component is illuminated by afirst illumination arrangement, said capturing of a first image isthereby providing a first illumination component;

capturing a second image of the first electronic component while thefirst electronic component is illuminated by a second illuminationarrangement, the second illumination arrangement being different fromthe first illumination arrangement, said capturing of a second image isthereby providing a second illumination component;

generating, by the use of software manipulation of the first image andthe second image, a plurality of generated images of the firstcomponent, wherein each one of the plurality of generated imagescomprises at least a specific combination of an illumination intensitylevel of the first illumination component and an illumination intensitylevel of the second illumination component;

selecting at least one of the plurality of generated images that fulfilsa predetermined quality measure;

determining, based on the selected generated image, an illuminationsetting associated with said package type, wherein the determinedillumination setting comprises at least a first intensity level for thefirst illumination component and a second intensity level for the secondillumination component.

2. The method according to claim 1, further comprising the subsequentsteps of:

capturing an image of a second electronic component of said specificpackage type while the second electronic component is illuminatedaccording to the determined illumination settings; and

determining, based on an analysis of the captured image, whether thesecond electronic component shall be discarded or placed on a workpiece.

3. The method according to claim 2, further comprising the subsequentsteps of:

capturing, in case it is determined that the second electronic componentshall be discarded, a verification image of the second electroniccomponent while the second electronic component is illuminated accordingto a verification illumination setting;

determining, based on an analysis of the captured verification image,whether the second electronic component shall be discarded or placed onthe workpiece.

4. The method according to claim 2, wherein the captured image isanalysed with regard to at least one of the following parameters: shapeor outline of the component, and position or orientation as held by amounting head of the pick-and-place machine.5. The method according to any one of the preceding claims, wherein thefirst component is held by a mounting head of the pick-and-place machineduring the capturing of the first and second images.6. The method according to any one of the preceding claims, wherein thepredetermined quality measure corresponds to a highest image contrast.7. The method according to any one of the preceding claims, furthercomprising:

capturing a background illumination image of the first electroniccomponent;

subtracting the background illumination image from the first image andthe second image prior to the generating of the plurality of generatedimages.

8. The method according to claim 5, wherein the background illuminationimage is added to the selected one of the plurality of generated imagesthat fulfils the predetermined quality measure, and wherein theresulting image is stored as a reference image to be used whendetermining whether a subsequent electronic component of said specificpackage type shall be discarded or placed on a workpiece.9. The method according to any of the preceeding claims, wherein:

the intensity level of the first illumination component, during thecapturing of the first image, is selected such that at least some pixelsof the first image are saturated or almost saturated; and/or

the intensity level of the second illumination component, during thecapturing of the second image, is selected such that at least somepixels of the second image are saturated or almost saturated.

10. The method according to any one of the preceding claims, wherein thefirst illumination component represents illumination of the componentfrom a first angle and the second illumination component representsillumination of the component from a second angle, the second anglebeing different from the first angle.11. The method according to any one of claims 1 to 9, wherein the firstillumination component represents illumination with light of a firstcolour and the second illumination component represents illuminationwith light of a second colour, the second colour being different fromthe first colour.12. The method according to any one of the preceding claims, wherein thefirst and second illumination components are selected from the listcomprising: dark field illumination, front light illumination, andambient illumination.13. The method according to any of the preceeding claims, wherein themethod further comprises uploading the determined illumination settingto an archive server.14. A system for verifying components, belonging to a specific packagetype, in a pick-and-place machine, the system comprising:

a first illumination arrangement for illuminating a first electroniccomponent of said specific package type by a first illuminationcomponent;

a second illumination arrangement for illuminating the first electroniccomponent by a second illumination component, the second illuminationcomponent being different from the first illumination component;

a camera for capturing a first image of the electronic component whileilluminated by the first illumination component and a second image ofthe electronic component while illuminated by the second illuminationcomponent;

a processing means configured to:

generate, by the use of software manipulation of the first image and thesecond image, a plurality of generated images of the first electroniccomponent, wherein each one of the plurality of generated imagescomprises a specific combination of an illumination intensity level ofthe first illumination component and an illumination intensity level ofthe second illumination component;

select at least one of the plurality of generated images that fulfils apredetermined quality measure; and

determine, based on the selected generated image, an illuminationsetting associated with said package type, wherein the determinedillumination setting comprises a first intensity level for the firstillumination component and a second intensity level for the secondillumination component.

15. The method according to claim 14, wherein the camera is furtheradapted to capture an image of a second electronic component of saidspecific package type while the second electronic component isilluminated according to the determined illumination setting, andwherein the the processing means is further configured to determine,based on an analysis of the captured image of the second component,whether the second electronic component shall be discarded or placed ona workpiece.16. An archive server, having at its disposal:

a first communication interface adapted to receive, from a systemaccording to claim 14, an illumination setting associated with a firstcomponent of a specific package type;

a storing unit adapted to store the illumination setting; and

a second communication interface adapted to provide the illuminationsetting upon request by a user.

17. The archive server according to claim 16, wherein the storing unitis adapted to store package data relating to the first electroniccomponent, and to complement the package data with one or severalillumination settings associated with the first electronic component.18. The archive server according to claim 17, wherein the archive serverfurther has at its disposal:

a third communication interface adapter to receive, from the systemaccording to claim 14, the images of a component captured by the camerawhen illuminated by the first and second illumination components.

19. The method according to any of claims 1 to 13, wherein the first andsecond electronic components are both illuminated by a first, a secondand a third illumination arrangement each providing a first, a secondand a third illumination component, wherein the first, second and thirdillumination components are all being different from each other.20. A system for verifying components, belonging to a specific packagetype, in a pick-and-place machine, the system further comprising:

a first illumination arrangement for illuminating a first electroniccomponent of said specific package type by a first illuminationcomponent;

a second illumination arrangement for illuminating the first electroniccomponent by a second illumination component, the second illuminationcomponent being different from the first illumination component;

a third illumination arrangement for illuminating the first electroniccomponent by a third illumination component, the third illuminationcomponent being different from both the first and second illuminationcomponent;

a camera for capturing a first image of the component while illuminatedby the first illumination component, a second image of the componentwhile illuminated by the second illumination component and a third imageof the component while illuminated by the third illumination component;and

a processing means configured to:

generate, by the use of software manipulation of the first image, thesecond image and the third image, a plurality of generated images of thefirst electronic component, wherein each one of the plurality ofgenerated images comprises a specific combination of an illuminationintensity level of the first illumination component, an illuminationintensity level of the second illumination component and an illuminationintensity level of the third illumination component;

select at least one of the plurality of generated images that fulfils apredetermined quality measure; and

determine, based on the selected generated image, an illuminationsetting associated with said package type, wherein the determinedillumination setting comprises a first intensity level for the firstillumination component, a second intensity level for the secondillumination component and a third intensity level for the thirdillumination component.21. The method according to claim 20, wherein the camera is furtheradapted to capture an image of a second electronic component of saidspecific package type while the second electronic component isilluminated according to the determined illumination setting comprisinga first intensity level for the first illumination component, a secondintensity level for the second illumination component and a thirdintensity level for the third illumination component, and wherein thethe processing means is further configured to determine, based on ananalysis of the captured image of the second component, whether thesecond component shall be discarded or placed on a workpiece.22. The system of any of claims 20 or 21, the camera of said system isfurther configured to capture a background illumination image of thefirst electronic component and to subtract the background illuminationimage from the first image, the second image and the third image.23. An archive server, having at its disposal:

a first communication interface adapted to receive, from a systemaccording to claim 20, an illumination setting associated with a firstcomponent of a specific package type;

a storing unit adapted to store the illumination setting; and

a second communication interface adapted to provide the illuminationsetting upon request by a user.

24. The archive server according to claim 23, wherein the storing unitis adapted to store package data relating to the first electroniccomponent, and to complement the package data with one or severalillumination settings associated with the first electronic component.25. The archive server according to claim 23 or 24, wherein the archiveserver further has at its disposal:

a third communication interface adapter to receive, from the systemaccording to claim 20, the images of a component captured by the camerawhen illuminated by the first, second and third illumination components.

1. A method for determining an illumination setting for capturing animage of a component, belonging to a specific package type, in apick-and-place machine, the method comprising: capturing a first imageof a first component of said specific package type while the firstcomponent is illuminated by a first illumination component; capturing asecond image of the first component while the first component isilluminated by a second illumination component, the second illuminationcomponent being different from the first illumination component;generating, by the use of software manipulation of the first image andthe second image, a plurality of generated images of the firstcomponent, wherein each one of the plurality of generated imagescomprises a specific combination of an illumination intensity level ofthe first illumination component and an illumination intensity level ofthe second illumination component; selecting at least one of theplurality of generated images that fulfils a predetermined qualitymeasure; determining, based on the selected generated image, anillumination setting associated with said package type, wherein thedetermined illumination setting comprises a first intensity level forthe first illumination component and a second intensity level for thesecond illumination component.
 2. The method according to claim 1,further comprising the subsequent steps of: capturing an image of asecond component of said specific package type while the secondcomponent is illuminated according to the determined illuminationsettings; and determining, based on an analysis of the captured image,whether the second component shall be discarded or placed on aworkpiece.
 3. The method according to claim 2, further comprising thesubsequent steps of: capturing, in case it is determined that the secondcomponent shall be discarded, a verification image of the secondcomponent while the second component is illuminated according to averification illumination setting; determining, based on an analysis ofthe captured verification image, whether the second component shall bediscarded or placed on the workpiece.
 4. The method according to claim2, wherein the captured image is analysed with regard to at least one ofthe following parameters: shape or outline of the component, andposition or orientation as held by a mounting head of the pick-and-placemachine.
 5. The method according to claim 1, wherein the first componentis held by a mounting head of the pick-and-place machine during thecapturing of the first and second images.
 6. The method according toclaim 1, wherein the predetermined quality measure corresponds to ahighest image contrast.
 7. The method according to claim 1, furthercomprising: capturing a background illumination image of the firstcomponent; subtracting the background illumination image from the firstimage and the second image prior to the generating of the plurality ofgenerated images.
 8. The method according to claim 5, wherein thebackground illumination image is added to the selected one of theplurality of generated images that fulfils the predetermined qualitymeasure, and wherein the resulting image is stored as a reference imageto be used when determining whether a subsequent component of saidspecific package type shall be discarded or placed on a workpiece. 9.The method according to claim 1, wherein: the intensity level of thefirst illumination component, during the capturing of the first image,is selected such that at least some pixels of the first image aresaturated or almost saturated; and/or the intensity level of the secondillumination component, during the capturing of the second image, isselected such that at least some pixels of the second image aresaturated or almost saturated.
 10. The method according to claim 1,wherein the first illumination component represents illumination of thecomponent from a first angle and the second illumination componentrepresents illumination of the component from a second angle, the secondangle being different from the first angle.
 11. The method according toclaim 1, wherein the first illumination component representsillumination with light of a first colour and the second illuminationcomponent represents illumination with light of a second colour, thesecond colour being different from the first colour.
 12. The methodaccording to claim 1, wherein the first and second illuminationcomponents are selected from the list comprising: dark fieldillumination, front light illumination, and ambient illumination. 13.The method according to claim 1, wherein the method further comprisesuploading the determined illumination setting to an archive server. 14.A system for verifying components, belonging to a specific package type,in a pick-and-place machine, the system comprising: a first illuminationsource for illuminating a first component of said specific package typeby a first illumination component; a second illumination source forilluminating the first component by a second illumination component, thesecond illumination component being different from the firstillumination component; a camera for capturing a first image of thecomponent while illuminated by the first illumination component and asecond image of the component while illuminated by the secondillumination component; a processing means configured to: generate, bythe use of software manipulation of the first image and the secondimage, a plurality of generated images of the first component, whereineach one of the plurality of generated images comprises a specificcombination of an illumination intensity level of the first illuminationcomponent and an illumination intensity level of the second illuminationcomponent; select at least one of the plurality of generated images thatfulfils a predetermined quality measure; and determine, based on theselected generated image, an illumination setting associated with saidpackage type, wherein the determined illumination setting comprises afirst intensity level for the first illumination component and a secondintensity level for the second illumination component.
 15. The methodaccording to claim 14, wherein the camera is further adapted to capturean image of a second component of said specific package type while thesecond component is illuminated according to the determined illuminationsetting, and wherein the the processing means is further configured todetermine, based on an analysis of the captured image of the secondcomponent, whether the second component shall be discarded or placed ona workpiece.
 16. An archive server, having at its disposal: a firstcommunication interface adapted to receive, from a system according toclaim 14, an illumination setting associated with a first component of aspecific package type; a storing unit adapted to store the illuminationsetting; and a second communication interface adapted to provide theillumination setting upon request by a user.
 17. The archive serveraccording to claim 16, wherein the storing unit is adapted to storepackage data relating to the first component, and to complement thepackage data with one or several illumination settings associated withthe first component.
 18. The archive server according to claim 17,wherein the archive server further has at its disposal: a thirdcommunication interface adapter to receive, from the system, the imagesof a component captured by the camera when illuminated by the first andsecond illumination components.